CRI听力:Genetically Modified Mosquitoes Reduce Zika Transmission

The Aedes aegypti mosquitoes have been discovered as the carriers of Zika, Dengue and other viruses.

Now researchers have come up with genetically modified mosquitoes to reduce their population in the wild.

Oxitec is the UK subsidiary of US synthetic biology company Intrexon. At the Oxitec lab in Brazil's San Paulo state, bio-engineer Karla Tepedino explains the process.

"We release the male mosquitoes, and they have a small genetic problem. The males don't bite or transmit any diseases, but they pass on these genetic defects to their offspring in nature, and their offspring are unable to survive. That way we are able to reduce the mosquito population, and without mosquitoes there are no diseases."

The transgenic insects have been proven effective. Between April and November last year, 25 million of them were released in a nearby neighborhood, where wild larvae of the Aedes mosquito were reduced by 82 percent.

That compares to the 30 to 50% of population reduction by the most effective chemical eradication programs for mosquitoes. Authorities also reported a big drop in Dengue cases in the area.

Derric Nimmo is in charge of product development at Oxitec. Holding a small container that fits into his hand, he says the modified mosquitoes can be easily transported.

"There's actually three million mosquito eggs in this pot, believe it or not. And we can ship these very easily around the world to different areas where we're treating the mosquito and trying to remove the mosquito with our technology."

The Zika virus was first detected in Africa in the 1940's. It was unknown in the Americas until last year when it appeared in Brazil.

Now spreading fast through Latin America and beyond, the virus has been linked to a neurological disorder called microcephaly, which causes small heads in new born babies.

The transgenic mosquito is named OX513A. Brazil's biosafety authorities have already approved it, but it needs authorization from the National Health Surveillance Agency before commencing commercial production.

The United States FDA is also reviewing the method for potential use in their country.

Brazil is scheduled to host the Carnival celebrations in two weeks. It is also the host of this summer's Rio Olympic Games. Tackling the outbreak and addressing international concern will remain a top priority for local health and tourism officials.

For CRI, I'm Victor Ning.